Season two of the Star Trek television series is an important one as it introduces characters which are still being used 40 years later. For instance, this is the season where Chekov makes his appearance. Different trends and themes that crop up time and time again in this and the many different spin off series make their appearance in season two. For these reasons it is seen as one of the more important of all 29 seasons of Star Trek and its subsidiaries.
Episode 1: Amok Time: Spock (played by Leonard Nimoy) must travel to Vulcan in order to undertake the Vulcan mating ritual.
Episode 2: Who Mourns for Adonais?: The crew of the Enterprise meet up with an alien who claims to be the Greek god Apollo.
Episode 3: The Changeling: What to do with an old Earth probe that is intent on sterilizing all it comes in contact with?
Episode 4: Mirror, Mirror: Captain Kirk (played by William Shatner) and three of his crew are transported to a mirror universe where greed and violence are the usual.
Episode 5: The Apple: Kirk tries to help a people who are being ruled by a computer named Vaal.
Episode 6: The Doomsday Machine: The crew of the Enterprise has to stop a doomsday machine that is capable of destroying multiple worlds.
Episode 7: Catspaw: An Enterprise landing party is missing except for the crew member is beamed back aboard dead. Kirk, Spock and McCoy (played by DeForest Kelley) decide to go investigate.
Episode 8: I, Mudd: A group of androids working for Harry Mudd (played by Roger C. Carmel) take over the Enterprise.
Episode 9: Metamorphosis: Kirk, Spock and McCoy's shuttle is diverted to a planetoid.
Episode 10: Journey to Babel: Spock meets his estranged father on the planet Babel.
Episode 11: Friday's Child: Kirk, Spock and McCoy travel to a planet in order to help negotiate a mining treaty.
Episode 12: The Deadly Years: A landing party is infected with a disease which ages you rapidly and causes senility.
Episode 13: Obsession: The crew of the Enterprise has to deal with a creature that feeds on human blood.
Episode 14: Wolf in the Fold: A serial killer is terrorizing a planet and Scotty (played by James Doohan) is the prime suspect.
Episode 15: The Trouble With Tribbles: Kirk has to try and stop a Klingon plot to destroy a grain shipment.
Episode 16: The Gamesters of Triskelion: Kirk, Chekov (played by Walter Koening) and Uhura (played by Nichelle Nichols) are kidnapped.
Episode 17: A Piece of the Action: The Enterprise arrive on a planet that behaves like it is 1920s Chicago.
Episode 18: The Immunity Syndrome: The Enterprise has to destroy a space amoeba before it begins to destroy the universe.
Episode 19: A Private Little War: Kirk becomes involved in an arms war with the Klingons.
Episode 20: Return to Tomorrow: The Enterprise meets up with intelligences without bodies who are trying to gain bodies to live in.
Episode 21: Patterns of Force: The Enterprise have to stop an historical researcher who has contaminated a society making them like the Nazis.
Episode 22: By Any Other Name: The Enterprise has to stop an invading alien people before they control the universe.
Episode 23: The Omega Glory: Looking into the disappearance of another starship, the Enterprise stumbles on an immortal people.
Episode 24: The Ultimate Computer: Starfleet asks the Enterprise to help it test out a supercomputer.
Episode 25: Bread and Circuses: The Enterprise comes up against a society that is very similar to that of ancient Rome.
Episode 26: Assignment: Earth: Kirk has to decide whether he is going to help or stop a traveler from the future who is being sent back to Earth in the 1960s on a secret mission.
Special Features: Original Previews, Star Trek's Favorite Moments, Writer's Notebook: D.C. Fontana, Life Beyond Trek: Leonard Nimoy, Kirk, Spock & Bones: Star Trek's Great Trio, Star Trek's Divine Diva: Nichelle Nichols, Billy Blackburn's Treasure Chest, BD-Live, Star Trek: TOS on Blu-ray, Easter Eggs